Tier 1 Graduate Entrepreneur Visa

Dear experts,

I have recently switched to Tier 1 Graduate Entrepreneurial visa from Tier 4. This new leave to remain is for a length of one year. These are main concerns:
1) Whether this one year will be counted towards the 5 year stay in the UK to apply for ILR or not?
2) The same question as above with regards to the time I have spent in the UK while I've been on Tier 4.
3) I'll switch to Tier 1 Entrepreneurial by the mid July 2015. Based on the current laws, will I be eligible to extend that visa after 3 years or not. I read through the Home Office documents, it seems that it is not allowed when the applicant has switched to this category and has not been granted this type of visa to enter to the UK?
Your comments will be highly appreciated.